/Engine/Source/Runtime/Engine/Public/Animation/AnimNodeMessages.h
Call the supplied function on the top-most node subscribed to the specified message in this stack
template<typename TGraphMessageType> void TopMessageWeakPtr ( [TFunctionRef](API\Runtime\Core\GenericPlatform\TFunctionRef)< void([TWeakPtr](API\Runtime\Core\Templates\TWeakPtr)< TGraphMessageType > &)> InFunction )